Electric arrangement for controlling electric lamps of a lamp screen



June 7, 1933. K ROSENBERG 2,119,870

ELECTRIC ARRANGEMENT FOR CONTROLLING ELECTRIC LAMPS OF A LAMP SCREEN Filed Nov. 24, 1934 2 Sheets-Sheet 1 4 E) 6 4- 5 6 INVENTOR BERG 7 8 g 7 8 9 KURT ROSEN a BY% AT ORNEY June 7, 1938. K. R N ERG ELECTRIC ARRANGEMENT FOR CONTROLLING ELECTRIC LAMPS OF A LAMP SCREEN Filed Nov. 24, 1954 2 Sheets-Sheet 2 llllllllllllllllllIlllllllllllll'lllJ r 37 lNVENTOR @1 KURT RosmBEnr-i I was A ORNEY Patented June 7, 1938 ATENT OFFICE ELEJTRIC ARRANGEMENT FOR OONTRBL- LING ELECTRIC LAMPS 'OF A LAMP SCREEN Kurt Rosenberg, Berlin, Germany, assignor, by rncsne assignments, to American Epok Inc.', New York, N. Y., a corporation of New York Application November 24, 1934, Serial No. 754,572 In Germany November 25, 1933 9 Claims.

Ihis invention refers to an electric arr-angementfor controlling electric lamps of any description but specially incandescent lamps, of a screen or any other apparatus adapted to reproduce pictures. In my copending application, Ser. No. 692,884, a feature of such arrangement and apparatuses is described.

One object of this invention is to improve the efficiency of such electric arrangements and to increase their-economy. In particular the invention aims to reduce the number of the discharge devices employed.

Another object of the invention consists in reducing the number of photo-electric cells employed for controlling the discharge gaps or devices-arranged in the circuits of the lamps of the screen in order to switch them in and out.

A further object of the invention consists in simplifying the supports of the photo-cells and the wiring.

Further objects of-the invention will be disclosed in the following description of several exemplificaticns of the invention.

In the drawings, Figure 1 shows schematically the wiring arrangement of a few photo-cells, each of which is'controlling two gas discharge tubes; Figs. 2 and 3 show the trains of half waves which result if the pairsof tubes shown in Figure 1 are fed by an alternating current; Figure 4 shows an arrangement adapted to be fed by a rectified alternating current; Figure 5 shows details of the switching over arrangement used in Figure 4; Figures 6, '7, 8, 9 show an arrangement and means for projecting pictures upon the controlling photo-cell according to one of the features of this invention; Fig. 10 shows an arrangement in which two controlled discharge tubes are combined into a single one according to another feature of the invention, and Figure 11 shows diagrammatically the trains of half waves as resulting when supplying the arrangement according to Figure 10 with alternating current.

In my co-pending application, Ser. No. 692,884, an electric arrangement for controlling electric lamps disposed in a lamp screen is described in which each of the electric lamps is coordinated to andsuitably connected in series with an individual electric gas-discharge tube which is provided with an auxiliary electrode having for instance the usual form of a grid. These grids are connected with photo-electric cells, which are arranged to forms. screen in the same way as the lamps form the displaying screen. Part-pictures may be projected upon the screen composed of said photo-cel1s which, if being illuminated, in-

block the gas: discharge device.

fluence the auxiliary electrodes of the gas discharge devices in such way that the co-ordinated lamps are lighted.

According to this invention as stated hereinbefore the number of discharge devices is reduced primarily thereby that some or all of the photo-electric cells are employed at the same time for controlling two or more such gas discharge gaps and, thereby, two or more lamps controlled by them. Hereby a substantial simplification and saving inthe costs of the apparatus and its operation is achieved. The gas discharge gaps controlled in this way may still be formed in separate tubes, or two or more such gridor otherwise controlled discharge gaps may be formed in the same vessel or tube, whereby further simplification and savings can be obtained.

Referring to the drawings, the-same reference numbers designate similar parts. In Figure l, photo-cells I, la are disposed in the circuit of an electrical source 2, e. g., in the form of a battery as shown. For simplification, only two such cells are shown whiletheir number practically app-lied depends on the number of lamps suitably used in the displaying screen. Each of the photo-cells is connected with auxiliary electrodes or grids 3, 3a, iii-discharge tubes 4, 4a and 5, 5a, respectively.

' Each pair or group of discharge devices l, ligand so on is controlled in this way by a single photocell i. ordinary type as known, e. g., under the registered trade-mark name Thyratron. Incandescent lamps 8, 3a. and 9, 9a, respectively, are coordinated to the discharge vessels 4, 4a,, and 5, 5a,

' respectively. A source of alternating/current l0 feeds the series arrangement of-incandescent lamps and coordinated discharge devices. The

preferably common source of A. C. The cathodes are suitably heated. A resistance II is arranged betweenthe cathodes of a pair of discharge devices, and a rectifier I2 is interposed in the connection of the cathodes in order to prevent a short-circuiting of them by the common gridbattery 2. The dimensions of theresistance II are such that only a small current of the lamp circuit can pass between the cathodes. It is known that .a negative potential is necessary to These discharge tubes may be of 13116;.

If the. cathodes of 2 vessels 4, 4a are connected by means of a resistance I I, then a phase current starting from one pole of source I9 and passing through one main to lamp groups 8a may continue to cathode I of vessel 4a, and then through resistance II to the cathode of the other vessel 4, returning to the second main which leads the phase current to the other pole of source I9. In this way any control of this phase current by the vessel 4a would be frustrated. In order to avoid this, a rectifier l2 has to be provided in the connection between the two cathodes. The same phase current can pass through the lamp groups 3, however, only if the grid 3 in the vessel 4 carries an according controlling charge. In the same way, in order to prevent a bypath for a phase current of inverse direction which could pass without control by the grids the cathodes first of vessel 4 and then of vessel 4a to enter the lamp groups 811 another rectifier I2a is provided. These rectifiers, preferably of the copper-oxide type also prevent any undesired charging of the grids of the vessels 4, 4a by the current feeding the lamp groups. are high-ohmic grid-resistances.

This arrangement operates in the following way. As it is well known, these discharge vessels have a rectifying effect, suppressing one-half wave of an alternating current supplied to them. Tracing the flow of current in Figure 1 from the source III in the direction of the lamps 8, 8a, one learns that a half wave flowing in this direction may pass the vessels 4 and 5 from the anodes to the cathodes thereof, while the vessels 4a and 5a, respectively, cannot be passed because of the inverse situation of their cathodes and anodes. Consequently, this half wave passing only the vessels 4, 5, lightens the lamps 8 and 9, respectively. At the subsequent half wave the direction of the current is inversed, which can pass then only the vessels 4a and 5a, respectively, lighting the lamps 8a and 9a respectively. Thus both trains of half waves are used alternately passing one of the two groups of tubes and lamps, lighting accordingly the latter ones.

Figures 2 and 3 show more schematically the two half wave trains. The positive train, Figure 2, is used for supplying the groups of lamps 8, 9, while the negative train of half waves, Figure 3, feeds the lamp groups 8a, 9a.

Figure 4 shows another arrangement according to the invention in which to each photo-cell two discharge devices are coordinated. The separation of the two half waves is secured by a special switching member 28. In this figure, I and la, respectively, designate the tubes coordinated to these photo-cells, which control the lamps 8 and 9. I0 is a source of current which supplies, however, in contradistinction to the A. C. supply in Figure 1, a rectified alternating current. One terminal of this source is connected with all cathodes I of the gas discharge devices, while the other terminal is connected with the contact arm of a commutator 29. The commutator divides the rectified alternating current supplied by the source I9 into two trains of half waves which are fed alternately to the conductors leading to the groups of lamps 8, 9, and 8a, 9a, respectively, whereby one group of lamps is fed with one-half wave of the pulsating current while the other group of lamps is fed with the other half-wave of this pulsating current. The commutator 29 operates synchronically to the frequency, thus leading each of the two trains of half Waves separately to each of the conductors. The switch 20 can be made as a commutator or an oscillating contact. The other parts in Figure 4 designated with the same reference-numbers as in Figure 1, have the same significance.

This arrangement according to Figure 4 operates in the following way. Supposing that the switch 28 connects the terminal I4 with the terminal I5, then the lamps 8, 9 are supplied with current and controlled by the coordinated photocells I, Ia. If, however, the switch connects terminals I4 and I6, then the lamps 8a, 9a are fed and controlled.

The switch 20 may also have the structure shown in Figure 5 in which a mechanical commutator controls grid-controlled gas discharge devices, which in turn control the larger currents feeding the lamp groups. In this way, very small currents of a few milli-ampere and volts sufllce to control the large currents passing the discharge devices.

In the feature according to Figure 5, the discharge tubes, particularly gas discharge tubes, I8, I9, having grids 2|, cathodes 22, anodes 23, filaments 24, are controlled by means of a mechanical commutator 20 shown in this figure as an oscillating contact. Depending upon the position of the switch 20, a blocking potential is applied from the source 25 on the grid of one of the discharge tubes I8 or I9. The discharge tubes I8, I9 are arranged in the path of conductor I4 leading from the source II] (Figure 4) to the two lamp groups. The cathodes 22 correspond in this case to the contacts I5 and I6, respectively, of Figure 4, which are coordinated to the lamp groups 8, 9, and 8a, 9a, respectively. If positioning the switch 20 in Figure 5, so that it is conrectified alternating current or a pulsating direct current is divided in such a manner that the lamp groups controlled by the discharge tubes I8 and I9, respectively, may alternately be fed by a half wave.

Instead of arranging a mechanical commutator, an alternating voltage may be used for alternately applying and removing a blocking voltage to and from the grids of the discharge tubes.

with the grids of the two tubes I8, I9, respectively, while the center of its secondary is connected with the two cathodes. Using a rectified alternating current, the controlling grids 2| may be combined advantageously with the rectifier. As described hereinbefore on hand of Figures 1 and 4, the single lamps of the lamp groups are controlled by gas discharge tubes. If illuminating a photo-cell I, the coordinated lamps 8, 8a are blocked because a blocking potential is applied on the grids 3. If illuminating periodically the photo-cells I in a frequency corresponding to that of the half waves, then optionally the one or the other half wave train can be blocked if the frequency of illuminating the cells is in phase with that of the half waves. Thus, the lamps 8 or 80., 9 or 9a may independently be controlled.

The following are the conditions of illuminating the photo-cells in phase with the half wave trains. It is supposed that a succession of pie- To this effect a transformer may be used, the ends of the secondary of which are connected IIv tures is to be projected upon the' field of photocells, and that these pictures form partof a film which is moved through the projector. These picturestogether form the intended display, each a of thempresenting only part of it and this therefore is called part-picture hereafter; Each of the'photo-cells operates like a transmitter of picture-points andcontrols, according to this invention, at least two lamps forming picture .points of the displaying screen. Therefore, if intending to project a sequence of part-pictures, at least two points of these pictures have to influence the same photo-cell.

are successively projected so that the photo-cells are. successively illuminated by the coordinated picture-pointsof the part-pictures. This may be described more in detail in view of Figures 7 and 8. Figure '7 shows a section througha diaphragm used for the purposes of the invention, while Figure 8 shows afront view of this diaphragm, with parts broken away,

The part-pictures a and b are projected 'by' means of an optical lens-system, prism or the like upon the photo-cell screen and replace each other successively. 'In Figure'l, the single-pic ture-points of the part-pictures a and 2), respectively, are projected in the direction of the arrows shown, upon the photo-cell screen26. .The lightbeams are supposed to be diverted by means of prisms notshown in this figure. In order to securethe successive projections of part-pictures a and b-upon the photo-cell screen in phase with the frequency of the half wave trains referred to herein before;a rotating diaphragm 2'! with cuts" 28 and 29 is arranged between the projector and the screen. =The cuts 28 and 29 are so disposed and of such dimensions that, if rotating the diaphragm with appropriate speed, each part-picture is covered-or uncovered during the period of ahalf wave.- Taking for instance; an alternating current of cycles per second and consequently consisting of half waves, taking furtherfour cuts in the rotating diaphragm, each cut covering about-90, then this diaphragm has to make 25 revolutions within a second. The diaphragm 2'! is arranged on a shaft 30 which is driven by any suitable means as for instance a synchronous motor. provided with phase regulating. means,

not shown in the drawings; There can be secured the rotation of the diaphragm in full synchronism and phase with the feeding current.

It is evident from the foregoing description .of any desired number of picture-points in any desiredmutual positiom- Furthermore, these two part-plctures may be steady, and consist in such casefor instance in so-called diapositives. Onemay provide, however, also a greater-number ,of such pairs of part-pictures and'project them successively" by any suitable'means upon thephoto-cell-screen; The part-pictures may be Thenwit is necessary to cover the projector tem- ,,por:arily r betweeir two successivepicture-frames Accordingly, Figure 6 shows two part-fields (or part-pictures) a and b of a film'to be projected, each of which is sub-' divided into a desirednumber of picture elements 1 to 9, which are to influence a coordinated photo-cell if being projected." The part-pictures? whereby a troublesome-flickering: of the -lamp screen is produced. 'In'order to overcome this disadvantage; preferably two -projectors 3|, 32

are provided as schematically shown in Figure"- 9 hereof;-in which 3!, '32 are the two projectors and 33 the common 'photo-cell-screen. The projectors operate in such way that one projector projects a part-picture-while the other one is covered, and vice'versa. Such covering can be don'e -eitherby rotating diaphragms as being delorill scribed in Fig-ures'Y, 8, or the rotating diaphragm usually provided in projectors of this kind'may be adapted and-usedlforthis purpose. Such-alter' natingicovering'and uncovering is to be done in synchronism with the sequence of the half waves,

and the duration of any illuminationof the photocell-scree-n-has to correspond'to the duration'of I each half-wave. 1. By using two projectors coordinated to two lamp'groups beingfed by'two half-wave trains, it is possible to dispose the transport of thefilm in the interval between two subsequent half waves as shown on Figure -2 hereof andbeing disclosed-more in detail in my co-pending applicationSerial-No.92,884. The

two projectors areoperated therefore in phase displacement of 180" or, in other words, the pro-' 7 jectionscare displaced for a frame-picture and for the'duration of a half-wave.

mon motor which may be a synchronous one so that the transport of the film is effected regularly within the time of the negative, butsupressed half The two pro'-' jectorsare driven preferably by means of a comwave as explained above in connection with Fig ures 2, 3.

While in the foregoing it has been shown how the arrangement can be simplified: by using'one sea.

photo-cell for the control of two discharge 'gaps arranged in two different discharge vessels, such as gas discharge tubes, Figures 10 and 11 show schematically a furtherv simplification according to my invention.- In Figure 10, =l and 1a are again photo-cells, 2 the electric source for the photo-- cells, 3 the grids of the switching discharge de-' vices being of the type of d'ouble-anode-tubes 34, 1

35, provided'with glowing cathodes of any de scription which are'heated in any suitable'wayL In thisexample, the cathodesare shown' as 'di--' rectly heated filaments 1. Two anodes 6, 6a are J connected in series with lamps 8, 8a and'9, 9a,

. disposed within each of the vessels -34, 35 and" respectively. Pulsating current is supplied by' means of a transformer 36, the endsof the sec odes 1 of the switching tubes. of the transformer is fed by a suitable source'of alternating current I0.

ondary 37 of which beingconnected to the oath-* The primary 38 t Because of the fact that the currents passing the lamps '8, 9, on one hand, and 8a, 9a'on the other hand, are displaced in phase for---,-="

- furthermore because-tubes of this kind are oper-'-' ating like rectifiers and permit" only the passing one half period the current 'may'fiow from one end of the secondary to the group of lamps 8, 9,

anodes 6, 6, cathodesl and back to the" center of the secondary, while during thenext half" period the current :is checked in this direction but allowed to flow from theotherend'of the secondary to the group of lamps *BaJSaJanodes 6a, 6a, cathodes .1 and backto. the "center :of combined; for instance, into-moving picturesr.

thehalfwave: train 12 passes. the..-lamps :8a,": 9a,

current impulses.

etc. The phases of the half wave trains at and b are displaced for The photo-cells l, l a are again common to two discharge gaps, one of which is formed between the anode 6 and the ,cathode "l and the other between the anode 6a and the cathode i in the same discharge vessels 34. The photo-cells are illuminated in the same way as described herein before.

The invention is not limited in any way to the examples shown herein but may be performed in any other way without deviating from the spirit of the invention which is described in its broadest aspect in the appended claims. So for instance, instead of only two part-pictures, a plurality of them may be used, and the frequency of the current feeding the lamps may be accommodated to the number of part-pictures chosen.

The arrangement according to this invention can be operated by using any kind of trains of The pulses may originate, for instance, from an alternating current or be obtained by subdividing a direct current by means of a commutator switch. Recurring pulses occur in both instances referred to by way of example. Any type of such current is covered by the term pulsating current in the appended claims, and any pulse produced, for instance, by subdividing a direct current or by applying the single phases of an alternating current, are termed pulses in the appended claims.

What I claim is:

1. An electric arrangement for displaying animated pictures and communications by means of a lamp field, comprising in combination groups of lamps of a lamp field, each group consisting of at least one lamp; discharge vessels each containing a number, including one, of anode and cathode electrodes forming a number, including one, of discharge gaps, and means for controlling the discharge through each of said gaps; means for connecting in series each of said gaps with a lamp group each and a source of pulsating current, thereby forming a lamp group-gap-series; light responsive devices arranged in a field adapted to be illuminated in accordance with an intended display of said lamp field, means for connecting and thereby associating each of said devices with said means controlling at least two of said discharge gaps, and thereby lamp groups connected in series therewith, and a source of current adapted to control at least part of said discharge, thereby forming a device-gap-group; and means for successively feeding pulses of said pulsating current to different lamp group-gapseries of said device-gap-groups, said pulses fed simultaneously to all said device-gap-groups whereby the actual passing of a current pulse through a lamp group just fed with it is controlled by an associated one of said devices depending upon its illumination.

2. In an electric arrangement according to claim 1, three mains for supplying a pulsating current, one of said mains to be interconnected with one pole of said current supply and an electrode of said gaps, the other two mains adapted to be intermittently and alternatively connected with the other pole of said current supply; means for interconnecting a part of said lamp groups with one of said latter mains and the other electrodes of part of said gaps, means for interconnecting the other part of said lamp groups with the other one of said latter mains and the other electrodes of the other part of said gaps; means for interconnecting said devices with the discharge controlling means of a gap each of both parts of said gaps and a pole of a second source of current for controlling said discharge, and means for connecting the cathodes of said gaps with the other pole of said latter source.

3. An electric arrangement for displaying animated pictures and communications by means of a lamp field, comprising in combination a multitude of lamp groups of a lamp field, each lamp group consisting of at least one lamp; discharge vessels each containing a plurality of discharge gaps formed between at least one cathode and a plurality of separate anodes, means for controlling the discharge through said gaps, means for connecting each anode of said gaps in series with a lamp group of said lamp field so as to form a multitude of lamp-gap-groups, a source of a number of recurring current pulses having a center point and a plurality of end points corresponding to its number of its recurring pulses, means for connecting each of said end points With different parts of said multitude lamp-gap-groups, means for connecting said center point with the cathodes of said vessels; light responsive devices arranged in a field adapted to be illuminated in accordance with the intended display of said lamp field, means for interconnecting, and thereby associating, each of said devices with said controlling means each and a second source of current adapted to control at least part of said discharge, whereby the passing of a current pulse through a lamp-gap-group is controlled by an associated one of said devices controlling the gap of said latter group depending upon its illumination.

4. In an electric arrangement according to claim 3, said source of recurring current pulses formed by the secondary of a transformer having a center point and terminals corresponding to the number of its recurring pulses, said center point connected with said cathodes and each of said end terminals connected with a lamp-gap-group each.

5. An electric arrangement for controlling lamps of a field, comprising in combination groups of lamps of a lamp field, each group consisting of at least one lamp; discharge vessels each containing at least an anode and a cathode forming a discharge gap, means for controlling said discharge, means for connecting in series each of said vessels with a lamp group each and a source of recurring current pulses; light responsive devices arranged in a field adapted to be illuminated, means for, and thereby associating, each of said devices with said means controlling at least two of said discharge gaps and a source of current adapted to control at least part of said discharge; means for feeding successively said recurring current pulses to different lamp groups connected and associated with each one of said devices; means for projecting a sequence of pictures upon said devices for illuminating them, and means for securing said sequence of illumination in phase with said recurring current pulses, whereby the passing of a pulse through a lamp group just fed with it is controlled by said illumination of an associated one of said devices controlling the discharge through a gap in series with said lamp group.

6. An electric arrangement for controlling lamps of a lamp field, comprising in combination lamp groups of a lamp field, each group consisting of at least one lamp; discharge vessels each containing a plurality of discharge gaps formed between at least one cathode and a plurality of separate anodes, means for controlling the discharge through said gaps, means for connecting the anodes of each of said gaps in series with a lamp group each so as to form a lamp-gapgroup; a source of recurring current pulses having a center point and a number of end points, corresponding to the number of recurring pulses of said current and of anodes present in said vessels, means for connecting each of said end points with a lamp-gap-group each connected with each of said vessels, means for connecting said center point with the cathodes of said vessels; light responsive devices arranged in a field adapted to be illuminated, each of said devices interconnected, and thereby associated, with the controlling means of said vessels each and terminals of a source of current adapted to control at least part of said discharge; a plurality of projectors each adapted to project intermittently pictures of a sequence of picturesupon said field comprising said devices, means for securing the projection of a picture by each of said projectors during an intermission in the projection by the others, and means for operating said projectors in phase with said current pulses.

7. In an electric arrangement according to claim 1, two mains for supplying said pulsating current, means connecting one part of said lamp groups and associated gaps for each device with one of said mains and an anode each of a part of said gaps and the cathodes with the other main; means connecting the other part of said lamp groups and associated gaps for last said device With the first mentioned main and a cathode each of the other part of said gaps and the anodes with said other main, means connecting the last said device with each controlling means of the gaps belonging to both of said parts and means connecting said devices With one pole of the second source of current for controlling said discharge; means for connecting the oathodes of all of said gaps to the other pole of said latter source of current, and means permitting the flow of current in one direction only inserted between said cathodes and said connecting means.

8. An electric arrangement for displaying animated pictures and communication by means of a lamp field, comprising in combination a multitude of groups of lamps of a lamp field, each group consisting of at least one lamp; discharge vessels each containing at least an anode and a cathode-forming a discharge gap, and a means for controlling said discharge; means for connecting in series each of said gaps with a lamp group each and a source of pulsating current; light responsive devices arranged in a field adapted to beilluminated, means for interconnecting each of said devices with said controlling means controlling at least tWo of said discharge gaps and a source of current adapted tocontrol at least part of said discharge; means for illuminating each device in accordance with the intended display of said lamp field; and means for successively feeding pulses of said pulsating current to diiierent parts of said multitude of lamp groups and gaps connected and associated with each one of said devices whereby the passing of a pulse through a lamp group just fed with it is controlled by said illumination of an associated one of said devices controlling the discharge through a gap in series with said lamp group.

9. An electric arrangement for controlling lamps of a lamp field, comprising in combination groups of lamps of a lamp field, each group consisting of at least one lamp; discharge vessels each containing at least an anode and a cathode forming a discharge gap, and an electrode for controlling said discharge; means for connecting in series each of said vessels with a lamp group each and a source of pulsating current; light responsive devices arranged in a field adapted to be illuminated, means for interconnecting each of said devices with said controlling electrodes controlling at least two of said discharge gaps and a source of current adapted to control at least part of said discharge; means for intermittently illuminating each device; and means for successively feeding pulses of said pulsating current to different lamp groups and vessels connected and associated with each one of said devices in synchronism with the intermittent illumination of the associated one of said devices whereby the passing of a pulse through a lamp group just fed with it is controlled by said illumination of an associated one of said devices controlling the discharge through a gap in series with said lamp group.

KURT ROSENBERG.

aim. a 

